气候变化领域集成服务门户(CCPortal): Diverse Structural Styles of the Northeastern Tethyan Himalaya in Southern Tibet Reveal the Early Collisional Tectonics of India and Asia

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DOI	10.1029/2023TC007954
	Diverse Structural Styles of the Northeastern Tethyan Himalaya in Southern Tibet Reveal the Early Collisional Tectonics of India and Asia
	Tang, Yu; Liang, Xiao; Wang, Genhou; Li, Dian; Qing, Zhanhui; Feng, Yipeng; Zhang, Wei; Han, Ning; Tian, Yang; Wang, Zhuosheng
发表日期	2024
ISSN	0278-7407
EISSN	1944-9194
起始页码	43
结束页码	3
卷号	43 期号:3
英文摘要	The poor understanding of the structural history of the Late Triassic flysch in the northeastern Tethyan Himalaya has caused many disputes regarding India-Asia collisional tectonics. Here, we conducted an integrated study including tectonostratigraphic analysis, structural analysis, and zircon U-Pb and muscovite 40Ar/39Ar dating to unravel the structural evolution of the Late Triassic flysch. Field geological mapping revealed that the flysch can be subdivided into three structural units, including the Gyaca melange, Qiongjie-Dengmu shear zone and Langjiexue fold-thrust belt. The three units all contain voluminous siliciclastic rocks deposited in an abyssal submarine fan environment at the Indian passive continental margin. The Gyaca melange shows a two-stage deformation process that generated a collisional melange resulting from the subduction of the Indian passive continental margin. 40Ar/39Ar dating of top-to-the-south shear bands and block-in-matrix structure indicate that the India-Asia collision happened no later than the Selandian (ca. 60 Ma). The divergent imbricated thrusting and folding of the Gyaca melange and Langjiexue fold-thrust belt formed a positive flower structure. The zircon U-Pb and 40Ar/39Ar dating of syntectonic dikes and sericite flakes within the Gyaca melange yield ages of ca. 56-55 Ma for the genesis of the divergent structures. Moreover, the Qiongjie-Dengmu dextral shear zone yields a sericite 40Ar/39Ar age of ca. 35 Ma and thus indicates a transient strike-slip stress regime. Generally, the early India-Asia collision tectonics in the northeastern Tethyan Himalaya showed episodic evolution with changing structural styles from melange formation to imbricate fold-thrust belt development and finally strike-slip shear generation. The Late Triassic flysch includes the Gyaca melange, Qiongjie-Dengmu shear zone and Langjiexue fold-thrust belt The bedding-parallel shear bands and block-in-matrix structure indicate that the India-Asia collision happened no later than ca. 60 Ma The Gyaca melange and Langjiexue fold-thrust belt formed divergent imbricated structures during the India-Asia collision at ca. 56-55 Ma
英文关键词	Tethyan Himalaya; structural style; deformation; collision; Melange
语种	英语
WOS研究方向	Geochemistry & Geophysics
WOS类目	Geochemistry & Geophysics
WOS记录号	WOS:001179925200001
来源期刊	TECTONICS
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/291975
作者单位	China University of Geosciences; China University of Geosciences; Chengdu University of Technology
推荐引用方式 GB/T 7714	Tang, Yu,Liang, Xiao,Wang, Genhou,et al. Diverse Structural Styles of the Northeastern Tethyan Himalaya in Southern Tibet Reveal the Early Collisional Tectonics of India and Asia[J],2024,43(3).
APA	Tang, Yu.,Liang, Xiao.,Wang, Genhou.,Li, Dian.,Qing, Zhanhui.,...&Wang, Zhuosheng.(2024).Diverse Structural Styles of the Northeastern Tethyan Himalaya in Southern Tibet Reveal the Early Collisional Tectonics of India and Asia.TECTONICS,43(3).
MLA	Tang, Yu,et al."Diverse Structural Styles of the Northeastern Tethyan Himalaya in Southern Tibet Reveal the Early Collisional Tectonics of India and Asia".TECTONICS 43.3(2024).